#include <stdio.h>
int fun(const char *s)
{
    int count = 0;
    char *p = (char *)s;
    while (*p != '\0')
    {
        if ((*p >= 48) && (*p <= 57))
            count++;
        p++;
    }
    return count;
}
int main(int argc, char const *argv[])
{
    char s[256] = {0};
    scanf("%s", s);
    printf("%d", fun(s));
    return 0;
}
